Tube forming apparatus



Jan. 22, 1935. w. H. ENGELBERTZ TUBE FORMING APPARATUS Filed March 17,1953 sheets-sheet 1 Jan. 22, 1935. w. H. ENGELBERTZ TBE FORMINGAPPARATUS Filed March 17, 1933 3 Sheets-Sheet 2 INVENTOR:

. W. H. ENGELBERTZ TUBE FORMING APPARATUS Jan. 22,

Filed March 17, 1933 3 Sheets-Sheet 3 INVENTORZ Patented Jan. 22, 1935 i1,988,547

NUNi'rr-:o vs'rxrizs PATENT OFFICE TUBE FORMING APPARATUS William H.Engelbertz, Pittsburgh, Pa. ApplicationvMarch 17, 1933, Serial No.661,22'1V Claims. (Cl. 29-33) This invention has reference toimprovements ances, previously there was the possibility of in tuberolling or drawing apparatus, which, for starting, i. e. re-advancing,said ram before a reason of brevity, will be referred to as tube newmandrel or billet had been brought into opforming apparatus hereafter,wherein a ouperating position. This danger is eliminated by 5 shaped,thick-walled, hollow. billet, carried by the invention, in providingmeans which auto- 5 the front end of a mandrel, is being forcedmatically interrupt the power supply of the ramthrough a succession'ofroll passes or through drive temporarily, until mandrel and billet ocanykind of suitable dies, which for brevity will cupy their pre-commencingposition and thereby be referred to hereafter as dies, which graduallyrestore the power Supply and Start the tubev reduce the wall-thicknessof the billet, thusforming operation automatically. 10 Y elongating itover the mandrel, whereby a tube A still further achievement of theinvention is with one dosed end is being formed. suitable the automaticcontrol of all movements o1' the means then separate tube and mandrelafter the tube-forming apparatus by cooperation of the tube has beenloosened somewhat on the manvarious devices, comprising said apparatus.

drel,'which may be accomplished, for instance, All advantagesoomprehended by thiS inven- 15 by passing cross-rolls, whereupon themandrel is tion Will be described more fully hereinafter, and broughtback to its initial position for re-use, Will be particularly pointedout in the appended while the tube receivesfurther treatment de- Claims.T0 enable those skilled in the art to pending on its nal destination,readily comprehend and practice this invention,

2o The principal object of this invention is, genreference should bemade te the accompanying 2o erally stated, to provide an apparatus ofthe drawings. Of courSe,Iwish to have it understood kind referred toabove, more effective and eithat it iS not my intention to conne orlimit cient than any kind practiced in this art at myself to any Speoiodetails of Construction depresent. These advantages will be effected by:Soribed or illustrated herein, Sinoe Changes and g5 1. Abontion of wasteof time and power; alterations will readily Suggest themselves to 25 2,Elimination 0f manual labor; Y thOSe- Skilled in this art WthOlltdeparting fl'Om 3. Decrease of production costs and increase the Spiritand Scope of the invention. of output rate. These will be achieved bycoop- The aooor ipanying drawings ShoW one preerating means to supplythe mandrel, t0 place it, fel'led embodiment 0f the invention inSomewhat :zu into operating position, to guide said mandreldiagramma/tical form in Whichwhile forcing the billet through the dies,and to Fig- 1 iS a plan View 0f the main part of the return the mandrel,after being freed from the apparatus; tube, to its initial position forfurther use. Fig. 2 is a diagrammatical side elevation there- Start andduration of all mandrel movements 0f, With the tube-forming operation.iuSt oomare timed, in accordance with the invention. pleted; 35

Further, the separation of tube .and mandrel, Fig. 3 is an enlarged sideelevation of the manafter the hold of the tube on the mandrel has d relkick-out device, taken on line A--A of Figbeen loosened, will beperformed by automatic 6; means and Without changing the direction ofthe Fig- 4 iS an enlarged Side elevation of another 4:) mandrel, thusmaking said separation a ltime mandrel kiek-Out'deviee, taken 0n lineB-B 0f 40 and energy saving procedure which preserves the Fig. 1; heatof the tube, thereby permitting further hot- Fig. 5 iS an enlarged Sideelevation of the biltreatment of the latter, such as passing a, reletreceiving table and means to open and close ducing or sinking millwithout reheating. a safety Switch, taken on line C-C of Fig 1I 43Another achievement of the invention is a FE 6 iS the Continuation ofFig- 1; 45

combined mandrel-locking-and-guiding device Fig. 'I is a front elevation0f the mandrel and operated by the incoming mandrel itself when tubeSeparating device in itS pre-acting position; moving into operatingposition; thus, an upset or Fig. 8 is the same as Fig. 7, lbut with thesepabuckling of the mandrel during the tube-forming ration of mandreland tube commencing; operation will be prevented. Fig. 9 is a.fragmentary side elevation of the 50 A further achievement of thepresent inventube and mandrel separating device; tion concerns thesecurity of the whole apparatus Fig. 10 is a. fragmentary frontelevation of vagainst damage. While the advance and reverse the startingmeans for the mandrel and tube stroke of the ram, which will bedescribed later, separating device, in rest position;

is being checked by well known electrical appli- Fig. 11 is one of thetube advancingrollers, 65

as part of the separating device, in enlarged scale;

Fig. 12 is an enlarged yertical cross section of the mandrel supplyingdevice;

Fig. 13 is the same as Fig. 12, showing the incoming mandrel;

Fig. 14 is the same as Figs. 12 and 13, showing the locked mandrel inoperating position;

Fig. 15 is an enlarged cross section of the mandrel-bar bearing,locking, and guiding means;

Fig. 16 is a fragmentary enlarged view, indicating in a somewhatdiagrammatic way the relative position of two levers keyed to one shaft,as part of Figs. 12, 13, 14;

Fig. 17 is a fragmentary enlarged partial section of the'mandrelbearing, with the mandrel in place.

The operation of the apparatus will be performed as follows: Referringto Fig. 1, after mandrel 1 has been brought into alignment with the ramconsisting of mandrel-bar 2 and rack 3, billet 4- will be placed ontable 5 located between said mandrel and dies 6, 7, 8, 9, the forwardmovement of ram-rack 3, driven by pinion 10 which in turn receives itspower from motor 11 over gear reduction unit 12, commences and forcessaid billet through said dies; thereby transforming billet 4 into atube.13, as shown by Fig. 2.

Power L is supplied to motor 11, which is of the D. C. type, from amotor generator set because the operating speed of the tube-formingapparatus shall be adjustable over a wide range. Current may be suppliedto motor 14 from any suitable source by wires 16, while other wires 17may be arranged to supply current to the ramdriving motor 11 for thepurpose of exciting its field. The driving power for motor 11 may betransmitted by wires 18 connecting the generator 15 with said motor. Noattempt has been made in the drawings to specifically indicate .thecontrol means and requisite wiring connecting the various units, as thedetails thereof form no part of the present invention and, are wellunderstood by those familiar with this method of controlling theoperation of adirectcurrent motor through a motor-generator set which iscommercially known as the Ward- Leonard principle or system of control.

The operation of the tube-forming apparatus is arranged so that motor 11will start and accelerate the ram and force it, with mandrel 1 andbillet 4 in front, through the passes of dies 6, 7, 8, 9 at apredetermined speed, reverse, and return the ram to its, initialposition. Mandrel 1 and tube 13 however, as practically one unit,proceed in forward direction by means of rollers 19 and pass a pair ofcross-rolls 20 whereby tube 13 is loosened on mandrel 1.

With the above preliminary understanding of the tube-forming processitself, including the loosening of the tube on the mandrel, both ofwhich have labsolutely no bearing upon the present invention, thevarious cooperating ldevicesemb0dying ,the invention, which now shall'point 23, thereby operating the starting switch 24 by s hiftinglever 25of said switch through "the medium of pivoting lever 26. Thus, the

`noid 29.

electric circuit between wires 27, 28 will be closed, wherebylelectricsolenoid 29 comes into action. This solenoid has a fourfold purpose at atime, namely, to give tube 13 free passage, to arrest mandrel 1, toadjust idler rollers 30 so as to cooperate with rollers 21, and toadvance tube 13 in'forward direction D. Fig. 7 shows the mandrel andtube stripping means in the resting stage, while Fig. 8 shows the samemeans in working position. Rod 31 of solenoid 29, being connectedwith,and raising levers 32, 33 about their pivots 34, 35, shown by Fig. 8,thereby raises the fork-shaped plate 36, by connecting means 37, 38, 39,over pivot 40, which keeps mandrel 1 in a stationary position and, onthe other hand, lowers mandrel and tube stopping means 41, 42, 43,- andmeans 44, 45, 46, the last three in the order stated, to put idlerrollers 30 into action for the purpose of advancing tube 13. -Each ofsaid rollers is supported by a forkshaped piece 47, bearing on spring 48in a cage 49 with lid 50 on top, shown in enlarged scale by Fig. 11.Idler rollers 30 are connected by cross-bars 46, as indicated by Figs. 7and 8. Cages 49 may have a fixed position and may be carried bystructural means 51, shown in dotand-dash lines by Fig. 9 which is afragmentary transverse view of Fig. 8.

Fig. 6 shows tube 13, freed from mandrel l, advanced by supportingrollers 21, after having turned down lever 52 mounted on shaft 53,thereby automatically operating, at a time, starting switch 54 byshifting lever 55 of said switch through the medium of pivoting lever56, and switch 57 through the medium of the same kind of lever-systemused for switch 54. Thus, the electric circuit between wires 58, 59 willbe closed and the mandrel kickout -is started by motor 60 over gearreduction unit 61, coupled thereto, and crank-shaft 62. Kickout shaft63, mounting a plurality of levers 64, is connected with crank-shaft l62by lever 65 and rod 66. One revolution of crank-shaft 62 effects anzdegree turn of levers 64, 65, thus kicking out mandrel 1, whereuponsaid levers return to their initial position The function of thiscommonly known kickout device is clearly indicated by Fig. 3. Also,through the downward turn of lever 52 by the advancing `tube 13, switch57 disconnects Wires 27, 27, thereby de-energizing sole- Thus, themeans, shown by Fig. 8, return into rest position, i. e. the initialposition shown by Fig. 7Minorder to be ready for the nextseparating'o'peration. The switches 54, 57 will be returned to theirinitial position by counter-weight167, as soon as lever 52 has beenreleased by the passing tube 13. The same action takesplac'e by themedium of counterweight 68 with regard to switch 24, as-soon as lever 22has been released'by mandrel l, i. e.

'after 'the' latter has been kicked oi the rollers 21. Thermandrelth'enrolls over skids 69 to the conveyingrolle'rs70 which advance saidmandrel in direction DD (Fig. 6) to the opposite end of the'conveypr, asfar as indicated in dotand-dash A.ltinef by Fig. v1.

' `In 2, the' ram,lconsisting of mandrel-bar 2 and.' rack3, is shown atthe end of its forward movement, i. e. in its position after fcompletion of the tube-forming operation. thej backward movement of theram, ,rar turns lever 71, mounted on shaft 72, th' operating theelectric starting switch '7 shifting lever 74 of said switch throug'medium of lever 75, keyed to shaft 72.' I

the electric circuit between wires 76, 77 and motor 78 will be' closed.Said motor, over the medium of gear reduction unit 79 and crank-y oflevers 83, 84 to a certain degree, thus lifting and delivering a mandrel1 from the cooling rack 86 for the following tube-forming operation,whereupon said levers return to their resting position. The function ofthis device is the same as for the mandrel kickout, shown partially byFig. 3. As said before, While a fresh mandrel is being delivered, a usedone will be ejected from the rollers to cooling rack 86 at a time. Thislast step has been illustrated by Figs. 1 and 4. The rotation of shaft82 in arrow direction results in the upward motion of plates 87, thuspushing mandrel 1 from rollers 70 to cooling rack 86. Shaft 88, carryinglevers 89, which in turn are connected with plates 87, and connectingmeans 90, 91, 92, 93 is the medium used in performing said mandrelmovement.

Finally,y said rotation of shaft 82 in arrow direction, indicated byFig. 5, temporarily interrupts the power-supply of the, ram-drivingmotor 11, so that said ram cannot be advanced for the next tube-formingoperation unless mandrel l and billet 4 are in a position, ready to beadvanced, vas shown by Fig. 1. This power interruption will be obtainedby the automatic operation of safety switch 81 which is disconnected bydouble lever 94, connected by rod to lever 96, the latter being keyed toshaft 82. Whiley the dot-and-dash lines in Fig. 5 show the levers 94 and96 in rest position, the heavy lines show said levers in a workingstage, i. e. the downward motion of finger 97 of switch 81 has just beencompleted by lever 94, thereby disconnecting the wires 18, 18, shown byFig. 1. The downward motion of finger 97 turns double lever 98 aboutpivot 99, thus bringing said lever into position to receive billet 4, asshown by Fig. 5. The return of shaft 82 to its initial position, causednaturally by the function of crankshaft 80, results in the return oflevers 94 and 96 to their rest position. Upon receiving billet 4, doublelever 98 is turned down. and rests again on table 5, while the upwardmotion of the other end of said lever-pushes finger 97 of contactor 81back to its initial position, thus reconnecting wires 18, 18, therebyrestoring the power-supply for the ram-driving motor 11, and startingthe next tube-forming operation automatically. Counter-weight 100,mounted on shaft 72, acts to bring lever 71 and therewith, switch 73back to their initial position, after said lever has been released bythe advancing ram-rack 3.

Figs. 12, 13, 14 illustrate the cooperating means which deliver, receiveand* lock mandrel 1, and which guide said mandrel advancing in directionD shown by Fig. 1i, during the tubeforming operation. The mandrel, whenlifted from cooling rack 86 by levers 83, indicated by Fig. 12, passesskids 101 and turns down the counterweighted arms 102, mounted on shaft103, shown yby Fig. 13, then rolls into operating position, shown byFig. 14, and rests on bearings 104, 105, which in turn are carried byhousing 115. The downward movement of arms 102, referred to before, willform an open gate, shown by Fig. 13, for the incoming mandrel by raisingupper guides 106, keyed to shaft 107.

The shafts 103 and 107, connected by levers 108, 109, rods 110, 111, andlevers 112, 113,' the last two keyed to shaft :114, act in unison. Alsoby the rotation of shaft 103, the lockingpins of upper guides 106 arewithdrawn lprior to the -upward motion of said guides. To assure this,lever 109, keyed to shaft 107, shows a keyway extension, indicated byFigs. 12, 13, 14, and in enlarged scale by Fig. 17. Thus, guide 106 canbe raised only after lever 1 09 has reached about thedotted-lineposition 'shown by Fig. 16. As soon as mandrel 1 has passed over arm102, counterweight 116 re-acts and brings said arm and all other movingparts described before, back to their initialposition, with mandrel 1 inplace and the upper ,guides 106 locked by pins 115. Now mandrel 1, whenadvanced in direction D in order to force billet 4 through the passes ofdies 6, 7, 8, 9, is prepared to meet the great axial stress imposed uponit during the tube-forming operation, since the provided series ofbearings 104, 105, and guides 106 prevent the mandrel from buckling orupsetting. One unit of the mandrel locking means, referred to above,comprises pin 115, spring 117, ball-joint 118, threaded bolt 119 forspring adjustment, and lever 120, keyed to shaft 103.

Figs. 12 to 15, inclusive and Fig. 17, indicate in dot-and-dash linesthe mandrel-bar holder 121, mounted on ram-rack 3, which is also shownfrom another point of view in Figs. 1 and 2. The mandrel-bar 2 isresting on bearings 122, 123, carried by housing 124, as shown by Fig.15. Said bearings with guides 125, as practically one unit when screwedtogether with bolt 126, form a locked, that is, rigid, guide for theadvancing mandrel-bar during the tube-forming operation.

When changing the mandrel-bar 2, that is, when the work program has tobe changed to another tube dimension, the nut of bolt 126 must be turnedback a few threads so that said bolt may be turned aside. After that,guide may be lifted and turned about pivot 128 by means of handle 127,whereupon mandrel-bar 2 can easily be liftedout of the, slotted holder121 by an overhead crane. It is obvious that the mandrel-bearings andguides 104, 105, 106, serve as such to mandrel-bar 2 also.

The linings 129, 130, 131, shown by Fig. 17, may be applied to themandrel-bar bearings and guides 122, 123, 125 as well as to the mandrelbearings and guides 1'04, 105, 106, in order to prevent said bearingsand guides from wearing out. On the other hand, such linings, with afinger-like extension, keyedl to the respective guides and bearings, asshown for example by Fig. 17, may have a varying bore, in order to besuitable for a wide range of mandrel and' pliances, for instance,automatically actingI photoelectric relays, may be utilized inaccordance with the invention.

This invention shall not be limited to the ecntrol of all mandrelmovements in the tubeforming apparatus but does include automaticcontrol of the start, forward stroke, and reverse (not shown on thedrawings) of the ram, consisting of mandrel-bar 2 and rack 3, thusmaking it practically impossible for the ram to overrun in eitherdirection. 2

'I'he foregoing description of the method of operating the tube-formingapparatus has disclosed how the -various devices are acting in unison sothat one movement automatically starts the succeeding one, after abillet 4 has been placed upon table 5. Thus, in fact, the automaticcontrol of all operations of the tubeforming apparatus, includingmandrel-handling, will be achieved by this invention.

A considerable reduction in operation costs by abolition of waste inenergy and time, obtained by most economical power vconsumption 'andelimination of manual labor, and the increase in production byspeeding-up and timing of all mandrel movements in order tov preservethe heat of the tube so as to permit the tube to pass a reducingorsinking-mill without reheating, are the benecial effects of thisinvention.

What I claim is:

1. In a tube forming apparatus, a push bench comprising, a series ofdies, a mandrel for a cupped billet, a ram connected to the mandrel andmeans for reciprocating the ram for advancing said mandrel with billettowards, and through, the dies at a predetermined speed whereby thebillet is formed into a tube over the mandrel, and for moving the rambackwardly to its initial position at a higher rate of speed, comprisinga motor, means connecting the ram and the motor wherebyvrotation of themotor in a predetermined direction is operative to impart movement tothe ram in a corresponding predetermined direction, a generator, meansfor driving the generator, connections between the generator and themotor, control means operative to vary the output voltage delivered tothe motor from the generator whereby the ram may be moved to and fromthe dies at desired speeds by varying said voltage, a safety switch,means connecting said switch with the ramdriving motor, means connectingsaid switch with the generator, mandrel-supplying means for timedplacement of a mandrel into working position, automatically acting meansconnected to the mandrel-supplying means for operating said switch whena mandrel is placed into working position causing disconnection of theramdriving motor and the generator whereby the backward motion of theram comes to an end, billet-receiving means for holding a cupped billetin alinement with the mandrel and the dies, automatically acting meansconnected to the billet-receiving means, for operating said switch whena cup-shapedbillet to be formed into a tube has properly been placedcausing reconnection of the. ram-driving motor and the generator wherebythe free moving laction of the ram is restored, and the tube-formingoperation is started, simultaneously.

2. In apparatus according to claim 1, means for expanding the diameterof the tube formed over the mandrel to loosen the hold of the tube onthe mandrel, a shiftable stop for halting the advancing tube with themandrel inside, means for conveying the tube with the mandrel from thetube expanding means to said stop, a solenoid, cooperating meansseparately connected with the solenoid comprising a shiftable mandrelgripper, a plurality of adjustable rollers, and said shiftable stop,means connected with the solenoid and extending into the path of tubeand mandrel causing action of said solenoid when the tube and mandrelreach said shiftable stop whereby the solenoid is operative to impartrelative movement to said shiftable stop, shiftable mandrel gripper, andadjustable rollers, simultaneously, thus effecting the arrest of themandrel and stripping or the tube from the mandrel, .means for furtheradvancing the tube, a switch, means connected with the switch andextending into the path of the advancing tube causing the start of saidswitch by said tube and eiecting de-energization of said solenoidwhereby said rollers, gripper, and stop return into rest position,mandrel kick-off means, a mandrel kick-off drive, and operativelyconnecting means between the kick-off drive and the kick-oir means, amotor for said drive, a switch started simultaneously with thefirst-mentioned switch by said tube by means connected with the switchand extending into the path of the advancing tube, means'connecting thesecondmentioned switch and the motor whereby the action of said switchis operative to impart relative movement to the mandrel kick-off driveand themandrel kick-off means effecting expulsion of the used mandrelfrom its supporting means, a transfer table so positioned as to receivethe ejected mandrel, conveying means so located as to receive themandrel from the transfer table and to advance the mandrel-,towards itsinitial position for re-use.

3. In a tube forming apparatus, a push bench comprising, a series ofdies, a mandrel for a cupped billet, a ram connected to the mandrel,means for reciprocating the rain for advancing said mandrel with billettowards, and through, the dies at a predetermined speed whereby thebillet is formed into a tube over the mandrel, and for moving the rambackwardly to its initial position at a high rate of speed, comprising aram-driving motor cooperating with a generator, control meansautomatically started by the advancing ram and adapted to stop theforward motion of said ram after the completion of the tube-formingoperation, and to reverse the polarity o the field of the generatorwhereby the direction of rotation of the ram-driving motor is operativeto impart movement to the ram in a corresponding predetermined directionand speed so as to move said ram back towards its initial position,mandrel-handling means, a

drive for operating the mandrel-handling means,

a motor for said drive, means connecting said drive with themandrel-handling means, a switch, means connecting the switch with themotor of said drive, mandrel cooling means and means' connected to saidswitch and extending into the path of the ram on its way vto the initialposition whereby said ram acts upon the last-mentioned means and saidswitch to cause relative movement of said drive and said mandrelhandlingmeans, thus eiecting the kick-up of a used mandrel onto said mandrelcooling means, and, timed delivery of a cooled mandrel for the nexttube-forming operation, so as to have the last-mentioned mandrel placedin proper working position, and said ram back in its initial position,simultaneously.

4. In a tube forming apparatus, a push bench comprising, a series ofdies, a mandrel for a cupped billet, a ram carrying a mandrel-barrigidly connected to the ram and detachably connected to the mandrelstationary mandrelbar receiving and guiding means consisting of ay`cupies its working' position therein, whereby said desired number oflockable chambers, means for reciprocating the ram for' advancing saidmandrel with billet towards, and through, the dies at a predeterminedspeedwhereby the billet is vformed into a tube over the mandrel, and formoving the ram backwardly to its initial position at a high rate ofspeed, comprising a ramdriving motor cooperating with a. generator,control meansautomatically started by the advancing ram and adapted tostop the forward motion of said ram after the completion of thetube-forming operation, and to reverse the polarity of the field of thegenerator whereby the direction of rotation of the ram-driving motor isoperative to impart movement to the ram in a corresponding predetermineddirection and speed so as to move said ram back towards its initialposition, mandrel-handling means comprising, a kick-up adapted to pickup one used mandrel at a time, a table constructed to take over, to cooland to move, said mandrel towards its working position, and a kick-off`of suitable design to deliver one cooled mandrel at a time for thetube-forming operation, a drive for operating the mandrel-handlingmeans, means con-- necting said' drive with the mandrel-handling means,mandrel receiving and. guiding, means comprising a desired number oflocked chambers spaced to each other and in alinement with thetube-forming dies, means operated by said cooled mandrel while movinginto working position to open said locked chambers for admitting saidmandrel, and automatic means for relooking said chambers after saidmandrel occhambers form a guide for said mandrel and mandrel-bar duringthe tube-forming operation.

5. In tube-forming apparatus including a push bench having a bedcarrying a plurality of mandreland mandrel-bar supports spaced to eachother in alinement with the tube-forming dies,v

a plurality of pivoted levers having their pivoting point xed on themandreland mandrelbar supports, means to lock the yfree end of thelevers to the mandreland mandrel-bar supports; means for conveying amandrel to the mandrel-supports and means actuated by the mandrel whilebeing so conveyed, to unlock and to turn aside a number of said leversto permit the mandrel to occupy its working position upon the supports,and to turn back -and to relock the levers to the mandrel-supports, thushaving the levers and the mandrel-supports act in unison to form aseries of guides for the mandrel during the tube-forming operation;means to unlock and to turn aside the remaining number of thefirst-mentioned levers to permit the mandrel-bar to be placed intoworking position upon the supports, means to turn back and to relock thelevers to the mandrel-bar supports, thus having the levers and themandrel-bar supports act in unison to form a series of guides forthemandrel-bar duringr the tube-forming operation; interchangeablelinings, attached to the levers and to the mandreland mandrel-barsupports, to form passes for the mandrel and mandrelbar during thetube-forming operation.

WILLIAM H. ENGELBERTZ.

